Stored Procedure Selects Wrong Records

I have a very simple data table that stores records of interventions teachers have with their students. I need to select records for a particular student recorded by a particular teacher of up to 3 different intervention types. If I select the record for one Intervention Type the query works perfectly. However, if I want to select the records of more than one type for a student the results are all the students that have the both intervention types.  It seems to ignore the student_id filter. Below is the table design, the proc that works when selecting one type the proc that doesn't work when trying to find more than one type.

The DB type is MS SQL 2008
TID is the Teacher's ID
CID is the Campus ID -- not used in query

Column Name                    DataType                 Allow Nulls
InterventionRecordNumb           int                                    No
InterventionType                         nvarchar(25)                   Yes
student_id                                   int                                     No
notes                                           nvarchar(MAX)               Yes
Intervention                                 varchar(MAX)                 No
TID                                               nchar(10)                        Yes
Incident                                        nvarchar(MAX)              Yes
CID                                               varchar(10)                    Yes
ClassroomStrategy                    nvarchar(250)                Yes

THIS PROCEDURE WORKS

SELECT     dbo.InterventionRecordIndex_local. InterventionRecordNumber, dbo.InterventionRecordIndex_local.student_id, dbo.InterventionRecordIndex_local.InterventionType, dbo.InterventionRecordIndex_local.TID
      FROM         dbo.InterventionRecordIndex_local
      WHERE       (dbo.InterventionRecordIndex_local.student_id = 1234) AND
            (dbo.InterventionRecordIndex_local.TID = 987) AND  
            (dbo.InterventionRecordIndex_local.InterventionType = 'Accommodation')
                         
THIS PROCEDURE DOESN'T WORK

SELECT     dbo.InterventionRecordIndex_local. InterventionRecordNumber, dbo.InterventionRecordIndex_local.student_id, dbo.InterventionRecordIndex_local.InterventionType, dbo.InterventionRecordIndex_local.TID
      FROM         dbo.InterventionRecordIndex_local
      WHERE       (dbo.InterventionRecordIndex_local.student_id = 1234) AND
                            (dbo.InterventionRecordIndex_local.TID = 987) AND  
                            (dbo.InterventionRecordIndex_local.InterventionType = N'Accommodation') OR
                            (dbo.InterventionRecordIndex_local.InterventionType = N'Modification')

I am sure there is some syntax I missed when learning how to write SP's. If you can help me out I would appreciate it. Thanks